Researchers and physicians are learning how to identify distinctive signs of COVID-19 from x-rays and CT scans, but so far these images are not offering many clues to predict which patients may pull through, according to an Associated Press report in the Los Angeles Times.

For now, doctors are relying on what’s called supportive care, which is standard for treating patients with severe pneumonia.

Doctors in areas still bracing for an onslaught of sick patients are scouring medical reports and hosting webinars with Chinese doctors to get the best advice on what has and hasn’t worked.

One thing that’s clear around the globe: Age makes a huge difference in survival. And one reason is that seniors’ lungs don’t have as much of what geriatrics expert Dr. Richard Baron calls reserve capacity.

“At age 18, you have a lot of extra lung capacity you don’t use unless you’re running a marathon,” said Baron, who heads the American Board of Internal Medicine. That capacity gradually declines with age even in otherwise healthy people, so “if you’re an old person, even a mild form can overwhelm your lungs if you don’t have enough reserve.”

Here’s what scientists can say so far about treating those who become severely ill.

Read more from the LA Times.

Featured image: Shown is a CT scan from a 65-year-old man in China with COVID-19. Pneumonia caused by the new coronavirus can show up as distinctive hazy patches on the outer edges of the lungs, indicated by arrows.(Mount Sinai Hospital via Associated Press)